We recently added up historic buildings and structures on the National Register of Historic Places that we’ve helped to preserve since 1992 (wow, more than 182!). Take a tour with your mouse through our Historic Preservation Brochure and celebrate #PreservationMonth with us!

At 289 feet tall, the dome of the United States Capitol towers over the eastern end of the National Mall in Washington, D.C., an instantly recognizable symbol of democracy. The cast iron dome itself was completed in 1863, after the nation’s rapid growth necessitated a remodel and expansion of the entire Capitol in the 1850s.

By the 1950s, however, the 9 million–pound dome had numerous fissures, and an attempt to weld them during a 1959–60 restoration was largely unsuccessful. The entire surface was cracking by 2014, prompting a three-year project that was completed in time for the 2017 Inauguration.